Caption: Slum housing. Family standing by a waste drainage ditch in a slum. Lack of proper sanitation can cause disease in slums where waste is not removed. This is Kiandi, part of Kibera slum in Nairobi, Kenya. The Kibera slum occupies a few square kilometres, and is home to some 700,000 people, some living ten to a room. A quarter of Nairobi's population live in this slum. Photographed in January 2006.